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Biomedical subjects

H Okazaki

Publications and source records attributed to H Okazaki.

At least 55 records · Page 3Linked to original sources
PubMed2000

Subarachnoid hemorrhage and systemic lupus erythematosus.

The frequency, clinical profile, treatment and outcome of subarachnoid hemorrhage (SAH) in patients with systemic lupus erythematosus (SLE) were assessed retrospectively, based on the case records of SLE of the Jichi Medical School Hospital over a 20 year period. Clinically defined SAH was found in 10 (3.9%) out of 258 SLE patients, which represented a frequency higher than previously assumed. Five patients had active SLE and lacked an apparent cause of SAH, other than SLE. A high mortality rate (5/5), no visible aneurysm on angiogram (3/4), and an onset during intractable SLE or after discontinued or no steroid therapy because of medical noncompliance (4/5) were characteristic of patients with active SLE, and thus an earlier successful suppression of SLE, if possible, might have prevented their SAH. In contrast, in the 5 patients with inactive SLE, 2 out of 3 saccular aneurysms were successfully clipped and small bleeding of one patient without aneurysms remitted spontaneously without the need for additional steroid therapy. When one death, which occurred outside of medical care, was excluded, the survival ratio of the hospitalized SAH patients with inactive SLE was significantly better than that with active SLE (3/4 versus 0/5, P=0.0476). In conclusion, the relatively common occurrence of SAH in SLE patients, and a significantly different clinical impact of SAH in respect to active and inactive SLE, were suggested from the results.

Adult↗
PubMed2000

Discrimination of alcoholic from virus-induced cirrhosis on MR imaging.

OBJECTIVE: The purpose of this study was to determine whether MR features help to differentiate virus-induced cirrhosis from alcoholic cirrhosis. MATERIALS AND METHODS: The MR examinations of 53 patients with cirrhosis (38 men and 15 women; age range, 28-73 years) caused by hepatitis B (n = 16), hepatitis C (n = 18), or alcohol abuse (n = 19) were retrospectively reviewed independently by two radiologists. The following MR features were assessed by each radiologist independently: volume indexes of the spleen and of each liver segment (based on 3-axis measurements), the nodularity of the surface, and the presence of regenerative nodules, ascites, iron or fat deposition, varices or collateral veins, the right posterior hepatic notch, and an expanded gallbladder fossa. RESULTS: The mean values of the volume index of the caudate lobe were significantly greater (p < 0.0001) in the group with alcoholic cirrhosis than those in the group with viral cirrhosis. The frequency of visualization of the right posterior hepatic notch in the patients with alcoholic cirrhosis was significantly greater (p < 0.05) than that in the patients with viral cirrhosis. The size of regenerative nodules of the liver in the patients with cirrhosis caused by hepatitis B was significantly greater (p < 0.02) than that in the patients with alcoholic cirrhosis. CONCLUSION: Enlargement of the caudate lobe and the presence of the right posterior hepatic notch on MR imaging are more frequent findings of alcoholic cirrhosis than of virus-induced cirrhosis.

Female↗
PubMed2000

[Autologous blood transfusion in surgery of urologic malignant tumor].

BACKGROUND: Autologous blood transfusion has been widely endorsed, because of the adverse effects attributed to homologous blood transfusion. So we employed autologous blood transfusion to avoid homologous blood transfusion in operation of urological malignant patients. We reviewed our experience with autologous blood transfusion in 48 patients. METHODS: A total of 48 patients underwent operation with 400 to 1,200 ml preoperative autologous blood donation, in 41 patients with administration of erythropoietin and 7 patients without erythropoietin. The details of operations are radical nephrectomy in 18 cases (2 cases were bilateral), radical nephro-ureterectomy in 2 cases, retroperitoneal lymph node dissection (RPLND) in 2 cases, radical prostatectomy in 12 cases and radical cystectomy in 14 cases. RESULTS: The volume of surgical blood loss were 381 +/- 522 ml in nephrectomy (1,158 +/- 202 ml in bilateral case), 517 +/- 5 ml in radical nephro-ureterectomy 636 +/- 574 ml in RPLND, 665 +/- 291 ml in radical prostatectomy and 1,123 +/- 417 ml in radical cystectomy. Only three cases needed homologous blood transfusion. CONCLUSION: We can avoid homologous blood transfusion in 94% of patients. Autologous blood transfusion is recommended as safe and convenient.

Adult↗
PubMed2000

Color Doppler sonography for evaluating response to transcatheter arterial embolization and percutaneous ethanol injection therapy and for detecting recurrence of hepatocellular carcinoma.

Eighty-six patients (mean age, 63 years) with 92 hepatocellular carcinomas (2.0 cm or greater in diameter; mean +/- SD, 3.5 +/- 1.6 cm) underwent color Doppler sonography before and after transcatheter arterial embolization and after subsequent percutaneous ethanol injection for (1) identification of pulsatile flow in the residual tumor area after transcatheter arterial embolization, (2) evaluation of therapeutic effectiveness of combined transcatheter arterial embolization and percutaneous ethanol injection, and (3) detection of recurrence during follow-up evaluation. Before and 2 weeks after transcatheter arterial embolization, color Doppler sonography revealed pulsatile flow in 76 (82.6%) and 43 (46.7%)lesions, respectively. After percutaneous ethanol injection, tumor stains in these lesions completely disappeared on digital subtraction angiography (gold standard). During follow-up study (3 to 45 months), digital subtraction angiography revealed recurrence in 73 patients (38 local recurrences and 19 new lesions [2.0 cm or greater]), whereas color Doppler sonography revealed pulsatile flow in 76.3% (local) and 63.2% (new) (not significant). Color Doppler sonography was useful for complying with our three objectives, especially for detecting local recurrence during follow-up evaluation.

Aged↗
PubMed2000

[Usefulness of temporal subtraction images of chest computed radiography for detection of metastatic pulmonary nodules].

Temporal subtraction is a technique by which a previous chest radiograph is subtracted from a current radiograph in order to enhance interval changes. Our purpose in this study was to evaluate the usefulness of temporal subtraction for the detection of metastatic pulmonary nodules. We examined 19 cases of metastatic nodules less than 15 mm in diameter (8.4 mm on average). Temporal subtraction images were created based on the matching of local lung areas in pairs of chest radiographs. By using the subtraction images, the detectability of nodules was clearly improved in 5 cases and moderately improved in 8 cases; there was no improvement in 6 cases. The subtraction images were especially useful for nodules superimposed over normal structures, such as rib, mediastinum, and diaphragm, as well as for small nodules. In 6 of the 19 cases, the nodules had been missed clinically; however, the temporal subtraction images clearly demonstrated half of missed small nodules. Temporal subtraction made it possible to enhance subtle interval changes and helped in detecting small pulmonary metastases. This technique seems promising for augmenting the capabilities of computed radiography of the chest.

Adult↗
PubMed2000

In vitro and in vivo inhibition of activation induced T cell apoptosis by bucillamine.

OBJECTIVE: To investigate the mechanism of autoimmune phenomena, occasionally seen in patients with rheumatoid arthritis treated with bucillamine (BUC) and D-penicillamine (D-Pen), by evaluating their effects on apoptosis of T cells induced by T cell receptor activation or dexamethasone. METHODS: In vitro apoptosis was induced in a T cell hybridoma (SSP3.7) and a B cell line (WEHI 231) by activation of respective receptors or dexamethasone, in the presence or absence of BUC or D-Pen. In vivo apoptosis was induced in BALB/c mice by staphylococcal enterotoxin B (SEB), with or without BUC or D-Pen, and thymocytes were examined for it by FACS. RESULTS: Stimulation with anti-CD3 and dexamethasone induced apoptosis in 72% and 71% of SSP3.7 cells, respectively. However, only 16% of SSP3.7 cells became apoptotic by anti-CD3 when BUC was added to the culture media. By contrast, 80% of SSP3.7 cells became apoptotic when stimulated by dexamethasone, even in the presence of BUC. BUC did not affect apoptosis of WEHI 231 cells induced by anti-IgM. Although SA981 (a metabolite of BUC) inhibited apoptosis of SSP3.7 cells induced by anti-CD3, D-Pen did not. BUC, SA981, or D-Pen did not significantly influence the level of interleukin 2 secretion stimulated by anti-CD3. In contrast, both BUC and D-Pen inhibited apoptosis of Vbeta8+ thymocytes induced in vivo by SEB superantigen. Neither BUC nor D-Pen significantly changed the number of CD4+CD8+ thymocytes in BALB/c mice injected with dexamethasone. CONCLUSION: BUC decreased, while D-Pen did not, the apoptosis of T cells stimulated by anti-CD3 in vitro, although they both inhibited the deletion of immature thymocytes reactive with SEB in vivo. This may explain autoimmune phenomena sometimes seen during the treatment of rheumatic patients with these drugs.

Animals↗
PubMed2000

[Rapidly progressed secondary amyloidosis in a patient with Still's disease with gamma-allele in his SAA 1 gene].

A fifteen-year-old boy was admitted to our hospital because of lower abdominal pain, watery diarrhea and mucobloody stool. Two years before admission, he was diagnosed to have Still's disease presenting with polyarthritis, sore throat, remittent fever and typical skin rash. He had been treated with non-steroidal anti-inflammatory agents, oral prednisolone and low-dose methotrexate. Although he was almost free of symptoms during the next two years, serum C-reactive protein (CRP) levels continued to be elevated moderately. He began to complain of lower abdominal pain and loose stool in May 1997 and came down with mucous-bloody diarrhea in June. Laboratory data on admission showed an elevated level of serum CRP (13.9 mg/dl). The biopsy of the stomach, ileum, sigmoid colon and rectum revealed the deposition of amyloid protein of AA type, which confirmed the diagnosis of secondary amyloidosis. The dose of prednisolone was increased and dimethyl sulfoxide per os or rectum was instituted, which improved his gastro-intestinal symptoms to some extent. However, fever, arthritis and diarrhea recurred along with tapered prednisolone dosage. In addition to gastro-intestinal symptoms, arrhythmia and proteinuria appeared. These symptoms were considered to reflect general deposition of amyloid in his body. He is now on immunosuppressive agent and high-dose prednisolone. Several studies report the higher frequency of gamma-allele of SAA 1 gene in the cases of rheumatoid arthritis with AA-amyloidosis than in those without. In the patient presented here, molecular biological analysis revealed that his SAA 1 gene was composed of beta- and gamma-allele. The presence of gamma-allele in his SAA 1 gene might be one of the factors that predisposed him for generalized deposition of amyloid protein in such a short period of time.

Adolescent↗
PubMed2000

[Clinical statistics on in-patients and operations during a 14-year period (1986-1999) at Department of Urology, Gunma Cancer Center].

The patients, diseases and operations experienced between 1986 and 1999 in our department were analyzed. The number of in-patients has been increasing since 1995. Renal cell carcinoma, urinary bladder cancer and testicular cancer have been gradually increasing recently, and in-patients with prostate cancer have increased markedly. Pelvic and ureteral cancers were almost constant during this period. Radical nephrectomy and prostatectomy have been increasing since 1994 and 1990, respectively. The examinations for malignancy, especially prostate biopsy, have been increasing.

Female↗
PubMed1999

A crucial role of sterol regulatory element-binding protein-1 in the regulation of lipogenic gene expression by polyunsaturated fatty acids.

Dietary polyunsaturated fatty acids (PUFA) are negative regulators of hepatic lipogenesis that exert their effects primarily at the level of transcription. Sterol regulatory element-binding proteins (SREBPs) are transcription factors responsible for the regulation of cholesterol, fatty acid, and triglyceride synthesis. In particular, SREBP-1 is known to play a crucial role in the regulation of lipogenic gene expression in the liver. To explore the possible involvement of SREBP-1 in the suppression of hepatic lipogenesis by PUFA, we challenged wild-type mice and transgenic mice overexpressing a mature form of SREBP-1 in the liver with dietary PUFA. In the liver of wild-type mice, dietary PUFA drastically decreased the mature, cleaved form of SREBP-1 protein in the nucleus, whereas the precursor, uncleaved form in the membranes was not suppressed. The decreases in mature SREBP-1 paralleled those in mRNAs for lipogenic enzymes such as fatty acid synthase and acetyl-CoA carboxylase. In the transgenic mice, dietary PUFA did not reduce the amount of transgenic SREBP-1 protein, excluding the possibility that PUFA accelerated the degradation of mature SREBP-1. The resulting sustained expression of mature SREBP-1 almost completely canceled the suppression of lipogenic gene expression by PUFA in the SREBP-1 transgenic mice. These results demonstrate that the suppressive effect of PUFA on lipogenic enzyme genes in the liver is caused by a decrease in the mature form of SREBP-1 protein, which is presumably due to the reduced cleavage of SREBP-1 precursor protein.

Animal Feed↗
PubMed1999

Preparation of recombinant rat interleukin-5 by baculovirus expression system and analysis of its biological activities.

Rat interleukin-5 (IL-5) cDNA was subcloned from peritoneal cells collected 4 h after intraperitoneal injection of Ascaris suum antigen solution into the immunized rats. Cysteine proteinase-deleted (CPd) rat IL-5 recombinant virus was constructed by inserting rat IL-5 cDNA into CPd virus having a deletion in the cysteine proteinase gene of the silkworm Bombyx mori nuclear polyhedrosis virus. On infection with the CPd rat IL-5 recombinant virus, the silkworm B. mori larvae produced rat IL-5 as a dimeric form in hemolymph. Recombinant rat IL-5 was purified more than 95.5% by anion-exchange chromatography and hydrophobic chromatography. The purified recombinant rat IL-5 promoted the proliferation of T88-M cells in a concentration-dependent manner, and its effect was inhibited by an anti-murine IL-5 neutralizing polyclonal antibody. When bone marrow cells from normal rats were incubated with recombinant rat IL-5 in medium containing methylcellulose, the colony formation by eosinophilic cells was induced. Furthermore, when rat peritoneal eosinophils were incubated with recombinant rat IL-5, the spontaneous decrease in the eosinophil viability was inhibited in time- and concentration-dependent manners. In addition, the recombinant rat IL-5-induced eosinophil survival was inhibited by an anti-murine IL-5 neutralizing polyclonal antibody. These findings suggest that rat IL-5 acts as B-cell growth factor II (BCGF-II), eosinophil differentiation factor (EDF), and eosinophil survival-enhancing factor.

Animals↗
PubMed1999

The effect of vesnarinone on TNF alpha production in human peripheral blood mononuclear cells and microglia: a preclinical study for the treatment of multiple sclerosis.

Vesnarinone (OPC-8212) is a synthetic quinolinone derivative with inotropic and immunomodulatory effects. Vesnarinone has been shown to inhibit tumor necrosis factor-alpha (TNF alpha) produced by mitogen stimulated macrophages, and to inhibit phosphodiesterase (PDE) type III in cardiac muscle. TNF alpha and interferon-gamma (IFNgamma) have been implicated in the pathogenesis of autoimmune diseases, and both cytokines are targets for therapeutic intervention. IFNgamma can enhance autoimmune disease through direct effects, and indirectly by priming macrophages to produce TNF alpha. In this study, we demonstrate that while vesnarinone enhances basal TNF alpha levels, it inhibits TNF alpha production in peripheral blood mononuclear cells from multiple sclerosis (MS) patients and healthy donors stimulated with lipopolysaccharide (LPS) or primed with IFNgamma and stimulated with suboptimal doses of LPS. In addition, vesnarinone inhibited TNF alpha production in primary adult human microglial cultures. However, in contrast to rolipram, another TNF alpha inhibiting agent, vesnarinone failed to inhibit TNF alpha production by myelin basic protein specific T-cell lines. As oral TNF inhibitors are currently being considered in the USA for clinical application in MS, the implications of our findings on the development of vesnarinone for treatment of MS are discussed.

Adjuvants, Immunologic↗
PubMed1999

The novel sphingosine 1-phosphate receptor AGR16 is coupled via pertussis toxin-sensitive and -insensitive G-proteins to multiple signalling pathways.

In the present study, we determined the agonist specificity and the signalling mechanisms of a putative sphingosine 1-phosphate (S1P) receptor, AGR16. In CHO cells transiently transfected with an AGR16 expression vector, but not in cells transfected with an empty vector, the addition of a low concentration of S1P (1 nM) caused an increase in the intracellular free Ca2+ concentration ([Ca2+]i) by mobilization of Ca2+ from both intra- and extra-cellular pools. To determine the spectrum of agonists for AGR16, we employed K562 cells, which in the naive state do not respond at all to either S1P or structurally related lipids with an increase in [Ca2+]i. In K562 cells stably expressing AGR16, S1P and sphingosylphosphorylcholine (SPC) dose-dependently increased [Ca2+]i with half-maximal values of 3 nM and 100 nM respectively. In CHO cells stably expressing AGR16 (CHO-AGR16), but not in parental CHO cells, we observed specific binding of [32P]S1P, which was displaced by unlabelled S1P and SPC. In CHO-AGR16 cells, but not in parental CHO cells, S1P stimulated the production of inositol phosphates and Ca2+ mobilization which was only 30% inhibited by pertussis toxin (PTX), different from the case of the recently identified S1P receptor EDG1. Also in CHO-AGR16 cells, but not in CHO cells, S1P at higher concentrations activated mitogen-activated protein kinase (MAPK) in a PTX-sensitive and Ras-dependent manner. S1P also induced the activation of two stress-activated MAPKs, c-Jun N-terminal kinase and p38, in a manner that was totally insensitive to PTX. In CHO-AGR16 cells, S1P induced stress-fibre formation, with an increase in myosin light chain phosphorylation, in a PTX-insensitive and Rho-dependent manner. S1P also induced an increase in the cellular cAMP content in CHO-AGR16 cells, which contrasts sharply with the case of EDG1. These results establish that the S1P receptor AGR16 is coupled via both PTX-sensitive and -insensitive G-proteins to multiple effector pathways.

Animals↗
PubMed1999

Detection of hepatocellular carcinoma: comparison of T2-weighted breath-hold fast spin-echo sequences and high-resolution dynamic MR imaging with a phased-array body coil.

The purpose of our study was to compare T2-weighted breath-hold fast spin-echo sequence (BHFSE) and high-resolution dynamic MR imaging (HR-DMRI) in the detection of hepatocellular carcinoma (HCC). Short and long T2-weighted BHFSE sequences and biphasic HR-DMRI including arterial-dominant and delayed phase images with a phased-array body coil were performed in 30 consecutive patients with 37 HCCs. The lesion-to-liver contrast-to-noise ratio (CNR) was quantitatively measured. The lesion conspicuity and delineation was qualitatively rated according to a four-point scale. The lesion-to-liver CNR was highest with the arterial-dominant phase HR-DMRI and was significantly higher than those obtained with both short and long T2-weighted BHFSE and those obtained with unenhanced and delayed HR-DMRI. The CNR obtained with short T2-weighted BHFSE was significantly higher than those obtained with long T2-weighted BHFSE and with unenhanced and delayed HR-DMRI. The sensitivity for the sequences was 78.4% (29/37) for short T2-weighted BHFSE, 67.6% (25/37) for long T2-weighted BHFSE, 37.8% (14/37) for unenhanced HR-DMRI, 97.3% (36/37) for arterial-dominant phase HR-DMRI, and 43.2% (16/37) for delayed HR-DMRI. The sensitivity of serial dynamic MR imaging combined with unenhanced, arterial-dominant phase imaging and delayed phase imaging was 100% (37/37). The score in the qualitative analysis of the lesion conspicuity and delineation was highest for the arterial-dominant phase HR-DMRI and was significantly higher than that for the short T2-weighted BHFSE. The score for the short T2-weighted BHFSE was significantly higher than that for the long T2-weighted BHFSE and that for the unenhanced HR-DMRI. Arterial-dominant phase HR-DMRI is superior to the T2-weighted BHFSE technique, and also HR-DMRI combined with unenhanced, arterial-dominant and delayed phases is the most sensitive technique in the detection of HCC.

Carcinoma, Hepatocellular↗
PubMed1999

Stimulation of bone formation by recombinant fibroblast growth factor-2 in callotasis bone lengthening of rabbits.

Bone lengthening by callotasis is one of the most useful methods not only for the treatment of short extremities but also for extensive bone defects; however, the procedure takes a long time especially for the consolidation of the distracted callus. In this study, effects of a single local injection of recombinant human fibroblast growth factor-2 (FGF-2 or basic FGF) on callotasis bone lengthening were examined in rabbits. Ten days after the osteotomy at the middle of the tibia and the installment of an external fixator, the osteotomized site was distracted at a rate of 1.4 mm/day for 7 days, resulting in 9.8 mm lengthening. On the final day of distraction, 200 microg of FGF-2 in 150 microl of saline solution or vehicle alone was injected into the center of the distracted callus. Injection of FGF-2 increased bone formation at the distracted callus radiologically and histologically. A significant effect on bone mineral content (BMC) at the callus was observed as early as 2 weeks, and FGF-2 increased the BMC about twofold at 5 weeks after a normal remodeling process. We conclude that the callotasis method in combination with FGF-2 injection at the consolidation step could be clinically beneficial to shorten the bone lengthening period.

Absorptiometry, Photon↗